Shimane Prefecture, at the heart of the San-in region, is the site of several celebrated religious shrines. The most important of these is Izumo-taisha, a few miles from Izumo. One of the oldest (its date of origin is unclear, though it is known to have existed in the eighth century), largest and most venerated pilgrimage destinations in the country, Izumo-taisha is where, it is believed, eight million spirit gods congregate for their official annual conference, migrating from all over Japan every October; everywhere except Izumo, October is known as the month without gods, since they are all presumably in Izumo, where October is called the month with gods.

Izumo-taisha is dedicated to Okuninushi, a descendant of the god and goddess who created Japan, and the deity in charge of fishing, silkworm culture and perhaps most important, happy marriages. Most likely, that explains why on a balmy Sunday afternoon the shrine—which consists of several structures surrounded by an extensive park—is crowded with multi-generational families and with a steady stream of ever-so-slightly anxious-looking couples who have come to admire the cherry blossoms and ask the gods to bless their unions.

As at every Shinto shrine, the faithful begin by symbolically purifying themselves, washing their hands and rinsing their mouths with water poured from delicate dippers hung above a trough. Then, approaching the main hall, they clap their hands to attract the attention of the gods, and bow to express respect. Some clap twice, others four times because four was the sacred number in ancient Japan; it was thought that both gods and people had four types of souls. It takes a certain amount of concentration for these newlyweds-to-be to focus on their heartfelt prayers while, all around them, people—children especially—are excitedly flinging coins into the air, trying to lodge them (doing so successfully is said to bring good fortune) in the huge, elaborately coiled straw ropes that guard the entrance to the central buildings. These ropes, thought to prevent unwelcome visitations from evil spirits, are characteristic of Shinto shrines, but the colossal ones at Izumo-taisha are unusually imposing.

In Izumo, a helpful young woman who tells us where to stow our luggage provides our first introduction to the patient sweetness with which the Japanese try to aid foreigners, even if it means locating the one person in the building—or the town—who speaks a little English, all of which makes traveling in this comparatively out-of-the way region easier and more fun than (as I had worried) daunting. From Izumo City, it's less than a half-hour by train, past farmhouses and kitchen gardens, to Matsue. The so-called "City of Water," bordered by the Tenjin River and by Lake Shinji, which is famous for its spectacular sunsets, Matsue also has an extensive system of moats surrounding its 17th-century castle. On clear days, a sparkly aquatic light blends the pinkish aura of Venice with the oceanic dazzle of the Northern California coast.

A 15-minute taxi ride from downtown Matsue is Tamatsukuri Onsen, the hot spring resort where we are staying and where the gods are said to enjoy an immersion in the healing waters. Running through this bucolic suburb is the Tamayu River, edged on both sides by blossoming cherries that shade groups of family and friends picnicking on the peacock-blue plastic tarps that are de rigueur for this 21st-century version of the ancient custom of cherry-blossom viewing.

The most familial, genially celebratory version of this time-honored custom is transpiring on the grounds of Matsue Castle on the late Sunday afternoon we visit. Lines of brightly colored stands sell toys, trinkets, masks, grilled squid and fried balls of dough stuffed with octopus. The most popular stalls offer still-warm egg cookies (shaped a bit like madeleines) and freshly baked bean-paste dumplings, playing to the (somewhat mystifying, to me) Japanese passion for what one might call extreme sweets. Meanwhile, on a shaded platform, a flute and shamisen orchestra produces the rippling phrases of classical Japanese music.

Matsue Castle rises like a stone wedding cake, its monumental walls supporting a series of terraced gardens. On its northern slope is a wooded park meticulously groomed to create the impression of untouched wildness. At the top of the hill is the castle itself, an ornate, harmonious, stately structure rising five stories and built in a fashion known as the "plover" style for its roofs, which rising to steep peaks and curving outward and upward, suggest the spread wings of a shorebird.

The castle is one of those places that make me wish I knew more (or to be truthful, anything at all) about carpentry, so that I could properly appreciate the craftsmanship that enabled the structure to be built without nails, assembled by artful joinery in what must be the supreme incarnation of tongue-and-groove construction. I can only admire the burnished richness of the wooden siding; the art objects, samurai helmets, antique kimonos; the historical murals and architectural models in the castle museum; and the vertiginous view of the distant mountains from the open platform on the highest floor.

Our capable companion, Chieko Kawasaki—many of the smaller Japanese cities and towns provide volunteer English-speaking guides through the municipal tourist bureaus, if you contact them in advance—explains the many superstitions associated with the castle. According to one, construction was plagued by problems until workers discovered a skull pierced by a spear; only after the skull was given a proper ceremonial burial did the building proceed smoothly. And as we stand on the top level, looking out over Lake Shinji, Chieko tells us that the island in the middle of the lake—Bride Island—is believed to have sprung up when a young wife, mistreated by her mother-in-law, decided to return to her family via a shortcut over the frozen lake. When the ice melted unexpectedly and she fell through and drowned, a goddess took pity on her and turned her into an island.

As Chieko speaks, I find myself thinking again of Lafcadio Hearn, and of the delight he took in hearing—and recording—such stories. In his essay "The Chief City of the Province of the Gods," Hearn repeats the tale, which he calls "The Island of the Young Wife." His summary is an abbreviated version of what Chieko has just told us. Perhaps the myth has continued to evolve and grow over the intervening decades, and perhaps it is as alive today as it was in Hearn's time, and in the centuries before that.